fix: keep dry runs off the docker daemon and speed up the tests (#1349)

Without a docker daemon six `act/runner` tests failed instead of passing. A dry run still created and removed job networks, the job teardown dropped the dry-run flag along with every other context value, and the container mocks asked the daemon for the runner arch.

This also speeds up the tests and CI without dropping assertions. Most of the time went to git and docker round trips, which are now pinned, batched or coalesced, and the dind and e2e steps cache or overlap more of their setup. On CI, `act/runner` went from 77s to 55s and `test-dind` from 108s to 55s. Locally, `act/runner` without docker went from 53s to 7s.

Split out of https://gitea.com/gitea/runner/pulls/1348, which adds Windows CI on top. The go cache changes moved to https://gitea.com/gitea/runner/pulls/1350.

Written by Claude Code.

---------

Co-authored-by: bircni <[email protected]>
Reviewed-on: https://gitea.com/gitea/runner/pulls/1349
Reviewed-by: bircni <[email protected]>
Co-authored-by: silverwind <[email protected]>

act/common/git/git_test.go

@@ -29,6 +29,31 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+var gitFixtureDir string
+
+func TestMain(m *testing.M) {
+	var err error
+	gitFixtureDir, err = os.MkdirTemp("", "runner-git-fixture-")
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+	code := 1
+	if err = gitCmd("init", "--quiet", "--template=", "--bare", "--initial-branch=main", filepath.Join(gitFixtureDir, "remote")); err == nil {
+		err = gitCmd("init", "--quiet", "--template=", "--initial-branch=main", filepath.Join(gitFixtureDir, "work"))
+	}
+	if err == nil {
+		code = m.Run()
+	} else {
+		fmt.Fprintln(os.Stderr, err)
+	}
+	if err := os.RemoveAll(gitFixtureDir); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		code = 1
+	}
+	os.Exit(code)
+}
+
 func TestFindGitSlug(t *testing.T) {
 	for _, testcase := range []struct {
 		remoteURL string
@@ -141,9 +166,8 @@ func TestGitFindRef(t *testing.T) {
 	} {
 		t.Run(name, func(t *testing.T) {
 			dir := filepath.Join(basedir, name)
-			require.NoError(t, os.MkdirAll(dir, 0o755))
-			require.NoError(t, gitCmd("-C", dir, "init", "--initial-branch=master"))
-			require.NoError(t, os.RemoveAll(filepath.Join(dir, ".git", "hooks")))
+			require.NoError(t, os.CopyFS(dir, os.DirFS(filepath.Join(gitFixtureDir, "work"))))
+			require.NoError(t, os.WriteFile(filepath.Join(dir, ".git", "HEAD"), []byte("ref: refs/heads/master\n"), 0o644))
 			for _, command := range tt.commands {
 				require.NoError(t, gitCmd(append([]string{"-C", dir}, command...)...))
 			}
@@ -180,6 +204,7 @@ func TestGitCloneExecutor(t *testing.T) {
 	t.Setenv("GIT_CONFIG_GLOBAL", hostConfig)
 	t.Setenv("GIT_DIR", t.TempDir())
 
+	var clones sync.WaitGroup
 	for name, tt := range map[string]struct {
 		Err error
 		Ref string
@@ -207,31 +232,34 @@ func TestGitCloneExecutor(t *testing.T) {
 			Ref: fullSha[:4],
 		},
 	} {
-		t.Run(name, func(t *testing.T) {
-			dir := t.TempDir()
-			clone := NewGitCloneExecutor(NewGitCloneExecutorInput{
-				URL: "https://example.invalid/action",
-				Ref: tt.Ref,
-				Dir: dir,
-			})
+		clones.Go(func() {
+			t.Run(name, func(t *testing.T) {
+				dir := t.TempDir()
+				clone := NewGitCloneExecutor(NewGitCloneExecutorInput{
+					URL: "https://example.invalid/action",
+					Ref: tt.Ref,
+					Dir: dir,
+				})
 
-			err := clone(t.Context())
-			if tt.Err != nil {
-				require.Error(t, err)
-				assert.Equal(t, tt.Err, err)
-				assert.Equal(t, tt.Err, clone(t.Context()), "a retry on the cache keeps the error")
-				return
-			}
-			require.NoError(t, err)
-			marker := filepath.Join(dir, "marker")
-			require.NoError(t, os.WriteFile(marker, nil, 0o644))
-			require.NoError(t, clone(t.Context()))
-			assert.FileExists(t, marker, "an insteadOf rewrite must not evict the cache")
-			script, err := os.ReadFile(filepath.Join(dir, "action.sh"))
-			require.NoError(t, err)
-			assert.Equal(t, "#!/bin/sh\necho hi\n", string(script), "host core.autocrlf must not convert action files")
+				err := clone(t.Context())
+				if tt.Err != nil {
+					require.Error(t, err)
+					assert.Equal(t, tt.Err, err)
+					assert.Equal(t, tt.Err, clone(t.Context()), "a retry on the cache keeps the error")
+					return
+				}
+				require.NoError(t, err)
+				marker := filepath.Join(dir, "marker")
+				require.NoError(t, os.WriteFile(marker, nil, 0o644))
+				require.NoError(t, clone(t.Context()))
+				assert.FileExists(t, marker, "an insteadOf rewrite must not evict the cache")
+				script, err := os.ReadFile(filepath.Join(dir, "action.sh"))
+				require.NoError(t, err)
+				assert.Equal(t, "#!/bin/sh\necho hi\n", string(script), "host core.autocrlf must not convert action files")
+			})
 		})
 	}
+	clones.Wait()
 }
 
 func TestGitCloneExecutorReclonesWhenOriginURLChanges(t *testing.T) {
@@ -476,9 +504,12 @@ func TestGitCloneExecutorPinnedHashIgnoresShadowingRef(t *testing.T) {
 func newGitRemote(t *testing.T, messages ...string) (string, string) {
 	t.Helper()
 	remoteDir, workDir := t.TempDir(), t.TempDir()
-	require.NoError(t, gitCmd("init", "--bare", "--initial-branch=main", remoteDir))
-	require.NoError(t, gitCmd("clone", remoteDir, workDir))
-	require.NoError(t, gitCmd("-C", workDir, "checkout", "-b", "main"))
+	require.NoError(t, os.CopyFS(remoteDir, os.DirFS(filepath.Join(gitFixtureDir, "remote"))))
+	require.NoError(t, os.CopyFS(workDir, os.DirFS(filepath.Join(gitFixtureDir, "work"))))
+	config, err := os.ReadFile(filepath.Join(workDir, ".git", "config"))
+	require.NoError(t, err)
+	require.NoError(t, os.WriteFile(filepath.Join(workDir, ".git", "config"),
+		fmt.Appendf(config, "\n[remote \"origin\"]\n\turl = %s\n\tfetch = +refs/heads/*:refs/remotes/origin/*\n", strconv.Quote(remoteDir)), 0o644))
 	for _, message := range messages {
 		require.NoError(t, gitCmd("-C", workDir, "commit", "--allow-empty", "-m", message))
 	}